Rotary engine.



Patented sept. 2, |902.

I No. 708,|29.

A. DAHLN. mmmv ENGINE, (Application tiled Aug. 2, 19017..)

` -4 Sheets-Shee't I.

(un Model.)

www.

No.'7oa,|29. Patented sept. 2, i902. y

IL'DAHLEN l Ronny enema..

(Application led Aug. 2, 1901.)

4 Sheets-Sheet 2.v

UNITED' STATES i PATENT OFFICE.

ANDREW DAHLN,OF VASAJVIINNESOTA,ASSIGNOR OF ONE-HALF TO H. L. BRYNILDSEN AND O.E. ANDERSON, OF VASA, MINNESOTA.

i. ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent N o; 708,129, dated September 2, 1902.

I Application iiled August 2, 19Q1. Serial No. 70,681. (No model.)

Improvements in Rotary Engines; and I do hereby declare the following to'be a full, clear, and exact description of the invention,

such as will enable others skilled in the art to 1o which it appertains to make and use the same. My present Ainvention hasfor its object to provide an improved rotary engine; and to 'this end it consists of the novel devices-and combinations of devices hereinafterdescribed, and deined in the claims.

The invention is illustrated in the accompanyingl drawings, wherein like characters indicate like parts throughout the several Views.

Figure 1 is a plan view with some parts broken away, showing an engine constructed in accordance with my invention. Fig. 2 is a side elevation of the engine looking from the lef-t with respect to Fig. 1, some parts being removed.. Fig. 3 isa view, principally in side elevation, looking from the rightwith respect to Fig. 1, but with some parts sectioned and others removed. Fig. 4 is avertical section on the line x4 x4 of Fig 1. Fig. 5 is a view corresponding toFig. 2, but with the cut-o valve and certain otherparts removed. Fig. 6 is a vertical section on the line m6 of Fig. 1; and Fig. 7is also a section on the line @c7 ofFig. 1, but showing the rotaryipistons y 5o the larger peripheral surface of which closely lits the coperating seat and extends approxi- The numeral lgindicates the cylinder-cast-l 'mately through one Ahundred and eighty degrees. Said segmental sections of the piston are provided near their extremities with trans- `verselyextended and radially removable 55 spring-pressed packing-blades 9. Said pistons throughout the other one hundred and eighty degrees of their circumference are reduced at Si, so as to aord propelling shoulders or surfaces 8".v The cylindrical surface of the 6o .larger segment of the one piston always closely engages the reduced cylindrical surface 8 of the other piston, and this engagement takes place between the saidpistons in alternate order.

The pistons 8 are vrigidly secured on theA shafts 10, which are suitably journaled in the cylinder-heads 3. Tocause the said rotary pistons 8 to move with properly-timedV action,

their shafts 10 are provided with intermesh- 7o ing-gears 1l. One of the said shafts 10 is provided at, one endwith a pulley 13, from which power maybe transmitted. To provide means for adjusting one of the pistons with respect to the other Ato compensate for wear, its shaft 10, instead of being mounted in ixedbearings ofthe cylinder-heads 3, is mounted in sliding bearings 14, which in turn ',Work with close-fittin g engagements in keeperguides 15, formed on the said cylinder-heads 8o 3. The 1 boxes 14 are yieldingly pressed inward by a' yoke 16, the ends of which engage i the same, which yoke is in turn drawn and held inward bya nut 17 on the stud 18,which -projects from the cylinder-casting and works through a central perforation in the said yoke.

A A steam-supply'pipe19 leads tothe supplychest 4, and an exhaust-pipe 2O leadsfrom the exhaust-chest 5. .Upper and lower pairs of admission-ports 21 and-22, respectively, open 9o into the piston-seats 2 through the4 left-hand cylinder-head 3. In a similar manner upper and lower pairs of exhaust-ports 23 and 24, respectively, open through the right-hand cylinder-head 3. It will be noted that of the pairs of ports 21, 22, 23, and 24eme member of each pair is located within the circumference of each rotary piston 8, so that they will be intermittently opened and closed by the said piston.

25 indicates a pivoted reversing-valve which cooperates with the admission-ports 21 and IOO 22 and is provided, respectively, with upper and lower pairs of ports 2l and 22. Likewise a vibrating reversing-valve 26 coperates with the exhaust-ports 23 and 24. This reversing-valve 26 is provided, respectively, with upper and lower pairs of exhaust-ports 23 and 24". The reversing-valves 25 and 26 are pivotally connected to stems 27, which work outward through suitable stnliiug-boxes 28 and the cooperating chests 4 and 5 and are connected at theironter ends, as shown in Fig. l, to a lever 29, pivoted at 30 to the cylindercasting l. The ports 2l:L and 22,respectively, ot` the reversing-valve 25 cooperate, respectively, with the admission-ports 2l and 22. The ports 23 and 2J. of the reversing-valve 26 cooperate, respectively, with thc exhaustports and 21.

A vibrating cut-off valve 3l, pivoted at 32, works over the face of the reversing-valve 25, and its upper and lower ends, respectively, eoperate directly with the ports 2l:L and 222 'lhe cnt-off valve 3l has an arm 33, to which the projecting arm of an eccentric 3a is pivotally connected. The eccentric 3,4 works on an eccentric 35, secured on one of the pistonshafts 10, as best shown in Figs. l and 2.

The operation is as follows: With the reversing-valves 25 and 26 set as indicated in Figs. 2, 3, 4, and 5 the two admission-ports 2l will be opened and the two admissionports 22 will be closed by the said valve 25, and the two lower exhaust-ports 24 will be opened and the two operative exhaust-ports 23 will be closed by the said valve 26. XVith the ports thus opened the rotary pistons S will be driven in the direction indicated by the arrows marked on Figs. 4, 6, and 7.

\Vhen not desired to run the engine under an expansion of the steam or motive Iiuid, the so-called cut-oit valve may be dispensed with. The said cut-off valve, however,serves to cut oi the steam or motive fluid and cause the pistons to be driven during part of their rotation under the expansion ot' the motive iiuid.

To reverse the direction of movement of the rotary pistons S, the two reversing-valves 25 and 26 are simultaneously moved into positions reversed from those shown in the drawings by movement imparted thereto by the lever 29 and stems 27. It desired, suitable means (not shown) may be provided for locking the lever 29 in its set position. XVhen said valves 25 and 26 are thus moved into reverse positions, the upper admission-ports 2l and the lower-exhaust-ports24 will be closed, while the lower admission-ports 22 and the upper exhaust-ports 23 may be opened. As is evident, in engines not designed to be reversible the valves 25 and 26 may be dispensed with, while in engines not designed to be reversible and not intended to be run under expansion the valves 25 and 26 and 3l, as well as the valve-gear for actuating the latter valve, may be dispensed with.

The segmental rotary pistons 8 of themselves act as valves to open and close the admission and exhaust ports in proper order. To illustrate: In the positions of the pistons indicated in Fig. 6 the right-hand admissionport 2l is closed by the cooperating piston, while the left-hand port 2l is open. Again, by reference to Fig. 4, which shows the same positions oli' the pistons, viewing the same from a reverse direction,the right-hand exhaust-port 24 is open, while tbe left-hand exhaust-port is closed by the coperating piston. Again, when the pistons have been rotated one hundred and eighty degrees, as shown in Fig. 7, the left-hand admission-port is closed and the right-hand admission-port 2l is opened. At this same time the exhaust-port 24 will be opened and closed in a reverse order from that above indicated. It is further evident that with an engine designed to run in but one direction two of the admission-ports and two of the exhaust-ports (shown in the illustration given) might be dispensed with. lt will also be understood that suitable means may be provided for preventing the springpressed packing-blades 9 from being thrown too far out of their seats in passing through the intersecting portions of the piston-seats.

From the foregoing description it is evident that the pistons in alternate order act as abutments. More specifically stated, in the position indicated in Fig. 6 the righthand piston is serving as an abutment for the left-hand piston, while in Fig. 7 the left-hand piston is serving as an abutment for the righthand piston. The piston-seats 2 are true cylinders, except where they are cut away by their intersection. The outer segments of the pistons 8 extendthrough arcs which are greater than the arc of intersection of the said piston-seats. With this construction the pistons in passing the intersected portions of IOO the piston-seats close the same for a considspecifically' set forth may be made within the l scope of my invention.

Vthat I claim, and desire to secure by Letters Patent of the United States, is as follows:

l. The combination with a cylinder having intersecting pistou-seats, of cooperating rotary pistons in said seats having reduced segmental sections intermeshing with the segmental body of the cooperating pistons, and admission and exhaust ports opening into TIO ` der, substantially-as described.

3. The combination with a cylinder having intersecting piston-seats and two pairs of admission and two pairs of exhaust ports opening into said cylinder, two admission-ports and two exhaust-ports opening to'each piston-seat, of cooperating intermeshing rotary pistons working in said seats and serving as Valves to open and close said ports in the proper order, and a pair of reversing-valves cooperating with said ports, substantially as described.

4. The combination with a cylinder having intersecting piston-seats and the pairs of admission and exhaust ports 21 22 and 23 24C, respectively, of the reversing-valves 25 and 26 having respectively, the ports 2liL 22L and .23ai 24a, connections for moving said valves simultaneously, and the intermeshing segmental rotary pistons working in said seats and serving as valves to open and close said admission and exhaust ports in the proper order, substantially as described.

5. The combination with a cylinder having intersecting piston-seats and pairs of admission and exhaustports opening into said piston-seats, of the reversing-valves cooperating with said admission and exhaust ports, the

vcut-oft valve cooperating with said admissionports, and the rotary segmental intermeshing pistons working in said seats and serving as I 

